signature help of tagged template doesn't show instantiated signature

[ajafff]

TypeScript Version: 2.9.0-dev.20180426

Search Terms:

Code

declare function tag<T>(string: TemplateStringsArray, ...values: T[]): void;

tag``;
tag`${1}`;
tag<number>``;

Expected behavior:

the following signature help when hovering over tag:

• function tag<{}>(string: TemplateStringsArray, ...values: {}[]): void
• function tag<number>(string: TemplateStringsArray, ...values: number[]): void
• function tag<number>(string: TemplateStringsArray, ...values: number[]): void

Actual behavior:

Signature help shows function tag<T>(string: TemplateStringsArray, ...values: T[]): void in all cases.

Signature help works as expected when calling tag directly using a CallExpression.

Playground Link: https://agentcooper.github.io/typescript-play/#code/CYUwxgNghgTiAEAzArgOzAFwJYHtXwygHMAeAFQD4AKAZwxi1SIC54yQBbAB2gxAGV6jIjQCCMGFACeAGngA6RQDcoEZCBqsyAbQC6ASlZKcWYAG4AUBcJEABrcs3bAEgDeARgC+D68RKpkDgAjEBgKezMgA

Related Issues:
#22873 same issue for JSX elements
#23492 PR for JSX elements

[mhegazy]

@DanielRosenwasser wanna take a look.

[DanielRosenwasser]

Funny thing I found was that

(foo)()

doesn't instantiate foo in quick info either, but maybe who cares

[DanielRosenwasser]

lol at Daniel from 4 months ago

[DanielRosenwasser]

Thanks @a-tarasyuk!